Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare that this is a non-read-only, idempotent, non-destructive mutation, and the description adds only that it updates an existing record by ID. It does not disclose important behavioral details such as whether unspecified fields are preserved, whether content or mark_points are replaced wholesale, or any permission requirements.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.